Industrial process and apparatus



p 24, 1958 E. E. RICHARDS 3,402,696

INDUSTRIAL PROCESS AND APPARATUS Filed March 11, 1966 2 Sheets-Sheet 1INVENTOR. EDWARD E. RICHARDS ATTORNEY p 24, 1968 E. E. RICHARDS3,402,696

INDUSTRIAL PROCESS AND APPARATUS Filed March 11, 1966 2 Sheets-Sheet 2 vINVENTOR. EDWARD E. RICHARDS ATTORNEY United States Patent 3,402,696INDUSTRIAL PROCESS AND APPARATUS Edward E. Richards, Warminster, Pa.,assignor to Pennsalt Chemicals Corporation, Philadelphia, Pa., acorporation of Pennsylvania Filed Mar. 11, 1966, Ser. No. 533,596 10Claims. (Cl. 118-125) ABSTRACT OF THE DISCLOSURE A wire coating diehaving split sections with a central orifice geometrically similar toand slightly smaller than the cross'section of the wire being coated.Flutes are circumferentially spaced about the orifice and have aperimetrical configuration whose periphery is also geometrically similarto the wire being coated and spaced therefrom by a substantiallyconstant gap which determines the coating thickness independently ofspeed as the wire is axially fed through the die. The die is embraced bya resilient member so that land portions of the orifice continuouslybear against the wire periphery.

This invention relates to wire coaters having means to apply anextremely thin coating of a plastic or other material for the purpose,for instance, of protecting the wire and/or beautifying the wire so thatit may be used for floral displays, for welding wire, for hair pins,coat hangers and so on.

In the prior art it has been customary to dip wire into a pool ofcoating material and to then wipe the wire with a lambs wool wipe.Drawbacks have been inherent in this process: the process has been slow;invariably the coating has been streaked and too thick. Flexibility ofthe coating has been limited. The nature of the coating has impaired theattractiveness and effectiveness of the finished wire.

Under the present invention the wire after passing through a reservoirpasses through a metering die. The die is serrated so that it contactsthe wire only at spaced intervals. The troughs or valleys of theserrations leave a space of small dimension between the wire and the diepermitting only a thin layer of coating material to escape through thedie and remain on the wire.

Once the wire is past the die, the material on the wire spreads itselfevenly about the entire circumference of the wire in an extremely thinwet film coating in the range of, for instance, .5 to 1.3 mils. Thecoating is thorough and flexible. At the same time remarkable speeds ofapplication of the material to the wire are obtainedin the neighborhoodof 250 ft./min., for instance. Such speeds are possible because thecuring of such a thin coat of material may be accomplished quickly andeffectively.

Other objects of the invention will be apparent to one skilled in theart from a review of the following specification including drawings,wherein:

FIGURE 1 is a view of the top plane of an apparatus embodying theinvention;

FIGURE 2 is a sectional elevational view taken on the line 22 of FIGURE1;

FIGURE 3 is an enlarged fragmentary view taken on the line 33 of FIGURE2;

FIGURE 4 is an enlarged fragmentary view taken on the line 4-4 of FIGURE2;

FIGURE 5 is an enlarged view, partly in section, from above, of a dieembodying the invention; and

FIGURE 6 is a sectional view taken on the line 6-6 of FIGURE 5.

Briefly, the invention relates to a coating assembly including acartridge and a rigid serrated die. The cartridge provides a sealedreservoir for the coating material, and

the die is split and is held in engagement with the wire which passestherethrough. The serrations of the die are extremely shallow to meterthe coating material which passes therethrough with the result thatafterward the coating material, still liquid, disperses itself about theentire circumference of the wire in an extremely thin coating.

In the preferred form the die is circumferentially split and the partsare biased together. Its opening measured across the peaks of theserrated opening when the parts of the die are together is slightly lessthan the diameter of the wire on which the device is used. In thisfashion there is always assurance that the peaks will contact the wireand that the distance between the wire and the troughs will be nogreater than a given distance.

Referring more specifically to the drawing, the wire coating assemblyembodying the invention is designated generally 10 in FIGURE 1. As shownin FIGURE 2 it comprises a cartridge having a cylindrical shell 12 and atop wall 14 and a bottom wall 16. The bottom wall is provided with asuitable packing gland 18 through which the wire W may pass withoutescape of coating fluid from within the cartridge. The gland comprises afabric or other compressible sealing material 20 adapted to becompresesd by the threaded plug 22 which is threadedly received into anappropriate opening in the bottom wall 16. The packing material 20 iscompressed against a suitable abutment 24 in the bottom Wall of thecartridge.

The cylindrical shell 12 is equipped with an inlet 26 and outlet 28 fora liquid coating material. This permits a circulation of the material bysuitable pumping means, not shown, to maintain uniformity of the coatingsuspension, for instance, or to heat.

The top wall 14 of the cartridge is provided with a central enlargedopening 30 over which is disposed the die holder 32. The die holder maybe centered by set screws 34 threadedly received into ears 36 extendingupwardly from the top wall 14. Plates 38 are boltingl secured to the topwall 14 and provide support against lateral movement of the holder 32.As shown, the holder 32 is provided with a central circular recess 40which receives the die proper 42.

The adjustment of the wire being coated laterally with respect to thedie is accomplished by the idler wheel 44. This is journaled in suitablebearings 46 (FIG. 1) on shaft 48 disposed in openings at the distal endof the bifurcated arm 50. The arm is held at the opposite end in anopening in a boss 52 mounted on the cylindrical shell 12 and extendingthrough an opening in the shell. The boss is closed by an end plate 54which threadedly receives the adjustment screw 56 which as shown (FIG.2) is grooved at 58 and held against a relative longitudinal movementwith respect to the arm 50 by a pin 60. As shown in FIGURE 3 the idler44 is formed with a peripheral groove 62 which engages the wire W.

By means of the arrangement shown, adjustment of the wire within the die42 is readily accomplished in the first direction by the adjustment ofthe set screws 34 and in the second direction by the adjustment of theadjusting screw 56.

As shown in FIGURE 5 the die 42 is basically cylindrical. Its diameteris smaller than the diameter of the recess 40. The die is split along aradial line 63. Pins 66 are provided in appropriate openings (FIG. 5) tohold the two parts in a precise alignment. It will be understood thatwhile the pins 66 fit snugly in their openings, the die may bedisassembled by simply pulling it apart with a force along the axialdirection of the pins facilitating interchanging dies without cuttingthe wire.

The die is biased in closely assembled position by means of anelastomeric O-ring 68 of neoprene or the like-resistant to the coatingmaterial. The opening in the I die. as measured across peaks 70 isslightly smaller in the completely assembled position than the diameterof the wire. For instance, if the wire is 12 gauge having a meandiameter of .1025 inch, the diameter measured across peaks is .1016 inchwhile the diameter measured across valleys is .1076. Hence the die isnormally held slightly open by the wire itself working against theresilient of the O-ring. In this manner the peaks 70 are in continuousrubbing engagement with the wire. Further, as the diameter of the wirechanges as it moves along the die may open or close slightly toaccommodate such changes. This breathing of the die in response tochanges in diameter of the .wire for a given gauge eliminates excessivewear on the die and scouring of the wire.

In the preferred form the troughs 72 or valleys of the serration areshallow-in the range of 2 to 5 millimetersand permit only a very smalllayer of coating material to pass through the die. Further, by havingthe recess 40 of greater diameter than the die 42 with the peripheralportion of the O-ring 68 engaging the peripheral wall of the opening 40,there is a cushioned lateral support for the die so that it may adjustto some extent to aberrations in the movement of the wire. The O-ring,however, tends to return the die to a central position in the recess.This is called a floating arrangement for the die. To enhance thismobility of the die, clearance is provided between the bottom surface ofthe die and the top surface of top wall 14.

As shown in FIGURE 6, the serrated opening 64 does not extend for theentire height of the die 42. Instead, a conical portion 74 is providedat the opening to avoid interference of the lower portions of the die 42with the wire.

In use the wire W is fed through the seal 18 up through the cartridgeand through opening 64 in the die 42. The set screws 34 and adjustingscrew 56 are set approximately. The liquid coating material is suppliedthrough the inlet 26 and the wire is moved upward as shown in FIGURE 2.Coating material is wiped from the wire on the circumferential portionswhich underlie the projections 70. A thin layer of coating materialescapes through the troughs 72 of the serration. Once through the die,the coating material disperses itself by action of surface tension aboutthe entire circumference of the wire W into a fine, thin coating whichmay then be cured 'by movement through an appropriate heated tunnel.

By virtue of the invention as claimed hereafter, extremely thin coatingof material can be applied to a wire at an extremely rapid rate. Thefloating die permits slight lateral movements of the wire W, andvariances in the diameter of the wire W are accommodated by the radialspread and contractions of the die sections. Because the coatings arethin they may be readily cured, and depending on the selection of thecoating material can provide remarkable flexibility and corrosionresistance, as well as an attractive appearance.

Wire as used herein is intended to mean any elongate workpiece and caninclude pieces of cross-section other than cylindrical.

The present invention may be embodied in other specific forms withoutdeparting from the spirit or central attributes thereof and,accordingly, reference should be made to the appended claims rather thanthe foregoing specification as indicating the scope of the invention.

I claim:

1. A coating for wire comprising:

a diametrically split die member having an orifice therein geometricallysimilar to and slightly smaller than the cross-sectional periphery ofthe wire,

circumferentially spaced flutes in the wall portion of the orificehaving a perimetrical configuration whose marginal peripheryisgeometrically similar to the cross-sectional periphery of the wire andspaced apart therefrom by a substantially constant predetermineddistance, and

means for resiliently urging sections of the die member toward the axisof the wire so that the latter is continuously compressively engaged byland portions of the orifice.

2. The coating device of claim 1 wherein the wire circular incross-section and said orifice is circular in configuration, theprojection of the marginal periphery of said flutes being circular andconcentric with the land portions of said orifice and said wire.

3. The coating device of claim 2 wherein said flutes are equally spacedcircumferentially about the orifice.

4. The coating device of claim 3 wherein the periphery of said flutes isradially spaced from the periphery of the wire by a distance in therange of 2 to 5 millimeters.

5. The coating device of claim 1 wherein said resilient means comprisesan elastomeric O-ring circumferentially embracing said die.

6. The coating device of claim 1 including a cartridge encapsulatingliquid coating material therein, means for slidably supporting said diewithin a resiliently constrained dispositon at one end of saidcartridge, means constituting a gland in said cartridge remote from saidone end, and means for feeding wire through said gland means into saidcartridge and into contact with the liquid coating material and then outthrough said die member orifice.

7. The coating device of claim 6 including means for adjustablypositioning the wire within the center of the resiliently constraineddisposition of said die member.

8. The coating device of claim 7 wherein said adjustable means includesa displaceable pulley.

9. The invention of claim 6 wherein said die member includes a taperedbore communicating with the orifice.

10. Apparatus for uniformly coating wire comprising: a split die havinga generally circular orifice centrally disposed therein and having across-sectional periphery slightly greater than the periphery of thewire, spaced apart land portions radially extending into the centerportion of the orifice and terminating at a position which is concentricwith the orifice and slightly smaller than the wire diameter, aconically tapered bore coaxial with and communicating with the orifice,and resilient means urging said land portions into contact with the wireperiphery, whereby uniform thin liquid coatings may be applied to thewire independently of Wire feed.

References Cited UNITED STATES PATENTS 2,062,389 12/1936 Bleibler 1181252,393,678 1/1946 Graham 118405 2,407,337 9/1946 Kolter. 2,875,725 3/1959Lit et al. 118125 2,952,240 9/1960 Abbott 118405 2,894,483 7/1959 Stahl1l8-125 XR 3,018,755 1/1962 Metcalf 118125 3,332,393 7/1967 Hoover118125 CHARLES A. WILLMUTH, Primary Examiner. ROBERT I. SMITH, AssistantExaminer.

